title: Connectivity between right inferior frontal gyrus and supplementary motor area predicts after-effects of right frontal cathodal tDCS on picture naming speed.
abstract: BACKGROUND
  Cathodal transcranial direct current stimulation (tDCS) of the right frontal cortex improves language abilities in post-stroke aphasic patients. Yet little is known about the effects of right frontal cathodal tDCS on normal language function.
  
  
  OBJECTIVE
  To explore the cathodal tDCS effects of the right-hemispheric homologue of Broca's area on picture naming in healthy individuals. We hypothesized that cathodal tDCS improves picture naming and that this effect is determined by the anatomical and functional connectivity of the targeted region.
  
  
  METHODS
  Cathodal and sham tDCS were applied to the right inferior frontal gyrus in 24 healthy subjects before a picture-naming task. All participants were studied with magnetic resonance imaging at pre-interventional baseline. Probabilistic tractography and dynamic causal modeling of functional brain activity during a word repetition task were applied to characterize anatomical and functional connectivity.
  
  
  RESULTS
  Subjects named pictures faster after cathodal relative to sham tDCS. The accelerating effect of tDCS was explained by a reduced frequency of very slow responses. tDCS-induced acceleration of picture naming correlated with larger volumes of the tract connecting the right Broca's area and the supplementary motor area (SMA) and greater functional coupling from the right SMA to the right Broca's area.
  
  
  CONCLUSIONS
  The results support the notion that the after-effects of tDCS on brain function are at least in part determined by the anatomical and functional connectivity of the targeted region.
authors.affiliation: CRICM - Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UPMC Paris 6, Paris, France; Inserm, U975, CNRS, UMR 7225 Paris, France; COGIMAGE, UPMC Paris 6, Paris, France; APHP, Urgences Cérébro-Vasculaires, Hôpital Pitié-Salpêtrière, Paris, France; Univ Paris 11, IFR49, DSV/I2BM/NeuroSpin, Bat 145, Gif-sur-Yvette 91191, France. Electronic address: charlotte.rosso@gmail.com.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Rosso
authors.affiliation: CRICM - Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UPMC Paris 6, Paris, France; Inserm, U975, CNRS, UMR 7225 Paris, France; Institut du Cerveau et de la Moelle épinière, Centre de Neuro-Imagerie de Recherche (CENIR), Paris, France.
authors.forename: R
authors.initials: R
authors.lastname: Valabregue
authors.affiliation: APHP, Urgences Cérébro-Vasculaires, Hôpital Pitié-Salpêtrière, Paris, France; Centre des Maladies Cognitives et Comportementales, IM2A, Hôpital Pitié-Salpêtrière, Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Arbizu
authors.affiliation: Centre des Maladies Cognitives et Comportementales, IM2A, Hôpital Pitié-Salpêtrière, Paris, France; APHP, Service de Soins de Suites et Réadaptation, Hôpital Pitié-Salpêtrière, Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Ferrieux
authors.affiliation: CRICM - Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UPMC Paris 6, Paris, France; Inserm, U975, CNRS, UMR 7225 Paris, France; COGIMAGE, UPMC Paris 6, Paris, France.
authors.forename: P
authors.initials: P
authors.lastname: Vargas
authors.affiliation: CRICM - Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UPMC Paris 6, Paris, France; Inserm, U975, CNRS, UMR 7225 Paris, France; Institut du Cerveau et de la Moelle épinière, Centre de Neuro-Imagerie de Recherche (CENIR), Paris, France.
authors.forename: F
authors.initials: F
authors.lastname: Humbert
authors.affiliation: CRICM - Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UPMC Paris 6, Paris, France; Inserm, U975, CNRS, UMR 7225 Paris, France; COGIMAGE, UPMC Paris 6, Paris, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Attal
authors.affiliation: Univ Paris 11, IFR49, DSV/I2BM/NeuroSpin, Bat 145, Gif-sur-Yvette 91191, France; Inserm, UPMC Univ Paris 06, UMRS 678, Laboratoire d'Imagerie Fonctionnelle, Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Messé
authors.affiliation: APHP, Service de Soins de Suites et Réadaptation, Hôpital Pitié-Salpêtrière, Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Zavanone
authors.affiliation: CRICM - Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UPMC Paris 6, Paris, France; Inserm, U975, CNRS, UMR 7225 Paris, France; Institut du Cerveau et de la Moelle épinière, Movement Disorders and Basal Ganglia: Pathophysiology and Experimental Therapeutics, Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Meunier
authors.affiliation: CRICM - Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UPMC Paris 6, Paris, France; Inserm, U975, CNRS, UMR 7225 Paris, France; COGIMAGE, UPMC Paris 6, Paris, France; Neuropsychologie et Neuroimagerie, UPMC Paris 6, Paris, France.
authors.forename: L
authors.initials: L
authors.lastname: Cohen
authors.affiliation: Neuroradiology Department, CHRU Roger Salengro, Lille, France.
authors.forename: C
authors.initials: C
authors.lastname: Delmaire
authors.affiliation: Danish Research Centre for Magnetic Resonance, University Hospital Copenhagen, Hvidovre, Denmark; Danish Technical University, Kgs. Lyngby, Denmark; MPI for Biological Cybernetics, Tübingen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Thielscher
authors.affiliation: Danish Research Centre for Magnetic Resonance, University Hospital Copenhagen, Hvidovre, Denmark.
authors.forename: D M
authors.initials: DM
authors.lastname: Herz
authors.affiliation: Danish Research Centre for Magnetic Resonance, University Hospital Copenhagen, Hvidovre, Denmark.
authors.forename: H R
authors.initials: HR
authors.lastname: Siebner
authors.affiliation: CRICM - Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UPMC Paris 6, Paris, France; Inserm, U975, CNRS, UMR 7225 Paris, France; COGIMAGE, UPMC Paris 6, Paris, France; APHP, Urgences Cérébro-Vasculaires, Hôpital Pitié-Salpêtrière, Paris, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Samson
authors.affiliation: CRICM - Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UPMC Paris 6, Paris, France; Inserm, U975, CNRS, UMR 7225 Paris, France; Institut du Cerveau et de la Moelle épinière, Centre de Neuro-Imagerie de Recherche (CENIR), Paris, France; APHP, Service de Neuroradiologie, Hôpital Pitié-Salpêtrière, Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Lehéricy
mesh_terms: D000328:Adult; D000368:Aged; D001931:Brain Mapping; D018592:Cross-Over Studies; D056324:Diffusion Tensor Imaging; D004558:Electric Stimulation / Q000379:methods*; D004566:Electrodes; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007802:Language; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology*; D055815:Young Adult
keywords: Diffusion tensor imaging; Functional magnetic resonance imaging; Language; tDCS